Convert Greenwich Mean Time to Iran Time
GMT · UTC+1 → IRST · UTC+3:30
GMT is 2 hours 30 minutes behind IRST
London · BST
Tuesday, 8 September 2026
Tehran · UTC+3:30
Tuesday, 8 September 2026
When are both sides at work?Each column is one hour of the day in the first city; the second row shows the same moment in the other city. Gold means office hours (09:00–18:00), dusk means awake but off work, night means asleep (23:00–07:00). Columns where both rows are gold are good meeting times.
Shared working hours: 09:00–15:30 in London is 11:30–18:00 in Tehran.
Working (09–18) Awake, off the clock Asleep (23–07)
Pick a time and share it
08:05 Tue 8 Sep London = 10:35 Tue 8 Sep Tehran
Hour-by-hour conversion
| London (GMT)Every hour of today in the first city, with the matching time in the second. “Next day” means the calendar date is already tomorrow there. The highlighted row is right now. | Tehran (IRST) | |
|---|---|---|
| 00:00 | 02:30 | |
| 01:00 | 03:30 | |
| 02:00 | 04:30 | |
| 03:00 | 05:30 | |
| 04:00 | 06:30 | |
| 05:00 | 07:30 | |
| 06:00 | 08:30 | |
| 07:00 | 09:30 | |
| 08:00 | 10:30 | Now |
| 09:00 | 11:30 | Both at work |
| 10:00 | 12:30 | Both at work |
| 11:00 | 13:30 | Both at work |
| 12:00 | 14:30 | Both at work |
| 13:00 | 15:30 | Both at work |
| 14:00 | 16:30 | Both at work |
| 15:00 | 17:30 | Both at work |
| 16:00 | 18:30 | |
| 17:00 | 19:30 | |
| 18:00 | 20:30 | |
| 19:00 | 21:30 | |
| 20:00 | 22:30 | |
| 21:00 | 23:30 | |
| 22:00 | 00:30next day | |
| 23:00 | 01:30next day |
About this conversion
GMT here means Greenwich Mean Time, represented by London (Europe/London), currently UTC+1. IRST means Iran Time, represented by Tehran (Asia/Tehran), currently UTC+3:30.
GMT is used by 22 zones, including United Kingdom. If you meant a different one, see every meaning of GMT.
Working hours are shown as 09:00–18:00 local, and sleeping hours as 23:00–07:00. The hour table is anchored on the current day in London; day boundaries are marked where the date differs.
Quick answers
- 09:00 GMT is 11:30 IRST
- 12:00 GMT is 14:30 IRST
- 15:00 GMT is 17:30 IRST
- 18:00 GMT is 20:30 IRST
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- Iran Time to India TimeIRST → IST
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- Eastern Time to Greenwich Mean TimeEST → GMT
- Eastern Time to Iran TimeEST → IRST
- Time in Londonnow, DST, offset
- Time in Tehrannow, DST, offset